Measurement of the local Jahn-Teller distortion in LaMnO{sub 3.006}

Journal Article · Fri Oct 01 04:00:00 EDT 1999 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.60.9973· OSTI ID:692530

Proffen, T; DiFrancesco, R G; Billinge, S J ^[1]; Brosha, E L; Kwei, G H ^[2]

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1. Department of Physics and Astronomy and Center for Fundamental Materials Research, Michigan State University, East Lansing, Michigan 48824-1116 (United States)
2. Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

The atomic pair distribution function (PDF) of stoichiometric LaMnO{sub 3} has been measured. This has been fit with a structural model to extract the {ital local} Jahn-Teller distortion for an ideal Mn{sup 3+}O{sub 6} octahedron. These results are compared to Rietveld refinements of the same data which give the {ital average} structure. Since the {ital local} structure is being measured in the PDF there is no assumption of long-range orbital order and the real, local, Jahn-Teller distortion is measured directly. We find good agreement both with published crystallographic results and our own Rietveld refinements suggesting that in an accurately stoichiometric material there is long-range orbital order as expected. The local Jahn-Teller distortion has two short, two medium, and two long bonds. This implies that there is some mixing of the d{sub 3z{sup 2}{minus}r{sup 2}} and d{sub x{sup 2}{minus}y{sup 2}} states and the occupied state is not pure d{sub 3z{sup 2}{minus}r{sup 2}} symmetry. The Debye temperature of the Mn and O ions has also been calculated as {Theta}{sub D}(Mn)=1000{plus_minus}100&hthinsp;K, {Theta}{sub D}(O{sub apical})=980{plus_minus}30&hthinsp;K, and {Theta}{sub D}(O{sub basal})=601{plus_minus}8&hthinsp;K. {copyright} {ital 1999} {ital The American Physical Society}

• OSTI ID: 692530
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 14 Vol. 60; ISSN 0163-1829; ISSN PRBMDO
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CHEMICAL BONDS
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
DEBYE TEMPERATURE
DISTRIBUTION FUNCTIONS
JAHN-TELLER EFFECT
LANTHANUM COMPOUNDS
LANTHANUM OXIDES
MANGANESE OXIDES
STOICHIOMETRY